Bluetooth Low Energy (BLE) is a low-power wireless technology developed by the Bluetooth Special Interest Group (SIG) for short-range communication. It is designed for control and monitoring applications and is expected to be integrated into billions of devices in the near future. This paper describes the main features of BLE, explores its potential applications, and investigates the impact of critical parameters on its performance. BLE represents a trade-off between energy consumption, latency, piconet size, and throughput, which mainly depends on parameters such as connInterval and connSlaveLatency. Theoretical results show that the lifetime of a BLE device powered by a coin cell battery ranges between 2.0 days and 14.1 years. The number of simultaneous slaves per master ranges between 2 and 5,917. The minimum latency for a master to obtain a sensor reading is 676 μs, although simulation results show that, under high bit error rate, average latency increases by up to three orders of magnitude. The paper provides experimental results that complement the theoretical and simulation findings, and indicates implementation constraints that may reduce BLE performance. BLE is a strong low-power wireless technology for single-hop communication use cases, which may contribute to connecting a dramatically large amount of new devices to the Internet of Things. It is expected to be used in billions of devices in the near future, and the IETF 6LoWPAN Working Group is developing a specification for the transmission of IPv6 packets over BLE. BLE is also suitable for healthcare, consumer electronics, smart energy, and security applications. It offers a trade-off between energy consumption, latency, piconet size, and throughput, and its performance is influenced by parameters such as connInterval and connSlaveLatency. BLE is also suitable for industrial environments, where it can handle multipath fading and radio interference from machinery. It uses adaptive frequency hopping, which offers a robust solution to these problems. BLE is also suitable for contactless applications, such as mobile payment, ticketing, or access control. It can be used in conjunction with NFC for pairing, which provides advantages of both technologies. BLE is also suitable for home automation and security applications, where it can be used for single-hop communication. The paper concludes that BLE is a strong low-power wireless technology for single-hop communication use cases, which may contribute to connecting a dramatically large amount of new devices to the Internet of Things.Bluetooth Low Energy (BLE) is a low-power wireless technology developed by the Bluetooth Special Interest Group (SIG) for short-range communication. It is designed for control and monitoring applications and is expected to be integrated into billions of devices in the near future. This paper describes the main features of BLE, explores its potential applications, and investigates the impact of critical parameters on its performance. BLE represents a trade-off between energy consumption, latency, piconet size, and throughput, which mainly depends on parameters such as connInterval and connSlaveLatency. Theoretical results show that the lifetime of a BLE device powered by a coin cell battery ranges between 2.0 days and 14.1 years. The number of simultaneous slaves per master ranges between 2 and 5,917. The minimum latency for a master to obtain a sensor reading is 676 μs, although simulation results show that, under high bit error rate, average latency increases by up to three orders of magnitude. The paper provides experimental results that complement the theoretical and simulation findings, and indicates implementation constraints that may reduce BLE performance. BLE is a strong low-power wireless technology for single-hop communication use cases, which may contribute to connecting a dramatically large amount of new devices to the Internet of Things. It is expected to be used in billions of devices in the near future, and the IETF 6LoWPAN Working Group is developing a specification for the transmission of IPv6 packets over BLE. BLE is also suitable for healthcare, consumer electronics, smart energy, and security applications. It offers a trade-off between energy consumption, latency, piconet size, and throughput, and its performance is influenced by parameters such as connInterval and connSlaveLatency. BLE is also suitable for industrial environments, where it can handle multipath fading and radio interference from machinery. It uses adaptive frequency hopping, which offers a robust solution to these problems. BLE is also suitable for contactless applications, such as mobile payment, ticketing, or access control. It can be used in conjunction with NFC for pairing, which provides advantages of both technologies. BLE is also suitable for home automation and security applications, where it can be used for single-hop communication. The paper concludes that BLE is a strong low-power wireless technology for single-hop communication use cases, which may contribute to connecting a dramatically large amount of new devices to the Internet of Things.